Ah, justification.
Well… I’m not a Palestinian, nor am I a Jew-baiting nutter, so anything I might have to say on the subject is speculation.
First of all, I don’t remember anything in the Koran against Christians or Jews specifically, although “unbelievers” are addressed. I don’t believe it said anything about “slaughter them mercilessly wherever you find them,” though.
On to the Shari’a, which is the basic Islamic code of behavior, a sort of written social more. It’s largely concerned with behavior and law. I don’t seem to remember anything there about slaughtering anyone you don’t like, although there are allowances for the death penalty and for maiming, for criminals found guilty of specific offenses. Then again, it is, literally, a medieval criminal code.
This leaves the Hadith, the collected utterances of the Prophet, which are often used to settle matters not covered by the Koran and the Shari’a. Unfortunately, we’re literally talking about the day to day words of the Prophet, many of which are open to interpretation by the listener.
If, for example, Mohammed (peace be unto him) had ever eaten brussels sprouts, and decided he did not like them, modern Egypt would probably make no comment about this… whereas, the Taliban might well have made the possession, sale, or consumption of brussels sprouts punishable by … well, you get the idea.
…and when you have crazy people, hateful people, or simply extremely stubborn people interpreting Holy Scripture… well… jeez, ANYTHING can happen.
Therefore, ANYTHING is justified.
Holiness is one thing.
The will of men is quite another.